Low power and Lossy Networks (LLNs), e.g., sensor networks, have a myriad of applications, such as Smart Grid and Smart Cities. Various challenges are presented with LLNs, such as lossy links, low bandwidth, battery operation, low memory and/or processing capability, etc. One example routing solution to LLN challenges is a protocol called Routing Protocol for LLNs or “RPL,” which is a distance vector routing protocol that builds a Destination Oriented Directed Acyclic Graph (DODAG, or simply DAG) in addition to a set of features to bound the control traffic, support local (and slow) repair, is etc. The RPL architecture provides a flexible method by which each node performs DODAG discovery, construction, and maintenance.
Energy, in particular, is a relatively critical and scarce resource in LLNs, especially when nodes are battery powered. In such an environment, saving battery life in the network has a direct impact on battery replacement cycle length (i.e., battery life). Extending battery life also has a direct impact on the cost of operating an LLN, as it reduces the aggregated cost of replacing batteries in the field. Existing networks reduce the energy consumption of nodes by switching the nodes between “sleep” and “active” states, which are typically a manually pre-set length of time. The longer time the nodes spend in sleep mode, the less energy they consume. However, as the sleep duration increases, the delay through the network may also increase, as there may be fewer nodes active (awake) at any given time through which traffic may be relayed.